unless the pedal feels really soft and spongy bleeding the lines probably wont make a difference, with the km it has and the fact that very few skylines have been babied there whole life i also think its probably a worn clutch. im kinda in the same boat actually, my clutch is worn and as such the engagment point is about 10/15mm from the end, instead of about 25mm where it would be with a good clutch. its still perfectly drivable, just have to be a little more carefull and not slip it away from lights etc.
ps. in my last post i meant to say pull type will be higher than the traditional push type